Demographic factors and the antihypertensive effect of diltiazem.

The maximum blood pressure (BP) decrease obtained after dose titration with calcium antagonists is said to be greater in older patients. Because the dose necessary to achieve this maximum effect may also vary, it is not clear whether the sensitivity to treatment is actually increased in older patients. We evaluated the possible influence of pretreatment BP, age, and weight on the BP and heart rate (HR) response to 14-day treatment with a fixed dose of 120 mg diltiazem twice daily (b.i.d.) in 231 hypertensive patients aged 24-82 years (44 +/- 27). Diltiazem decreased BP from 171 +/- 1/103 +/- 7 to 156 +/- 1/91 +/- 1 mm Hg. Decreases in both systolic and diastolic BP (SBP, DBP) were related to their pretreatment values (p less than 0.0001 for both). Although pretreatment SBP was related to age (p less than 0.0001), its decrease with diltiazem was not. Neither pretreatment DBP nor its decrease with diltiazem was related to age; BP decrease was not superior in elderly patients (aged greater than 60 years) as compared with that in younger patients (SBP -16 +/- 2 vs. -15 +/- 1 mm Hg, NS; DBP -13 +/- 1 vs. -12 +/- 1 mm Hg, NS). In conclusion, the response to this average dose of diltiazem is related to pretreatment BP and is not affected by patient's age. Because this result is at variance with the concept that calcium antagonists are more effective in the elderly, this concept should not be used as a general therapeutic guideline.